Wendy's Complaint - Attitude of server - Shorted order

I placed an order for a spicy chicken sandwich combo and was shorted the sandwich. I alerted the server of the oversight and was told that the sandwich had been placed in the bag and insinuated that I had removed the sandwich from the bag. This was a total shock to hear this employee imply that there had not been a mistake and there had been some deception on my part. I offered them the opportunity to check the vehicle if they felt they could uncover the missing sandwich which they declined to accept. They ultimately provided the sandwich, and I left, but I was repulsed by the attitude of the server.